There is near universal acceptance of the view that imitative processes play an important role in the early cognitive and social development of the child. We argue that imitation also plays a role in the acquisition of speech, noting that both the phonetic and the prosodic features of a particular language are learned very early in life. Recent experiments in our laboratory suggest that infants' ability to imitate has been underestimated by traditional developmental theories. Our research shows that infants in the first six months can imitate facial gestures -- a skill that was postulated to appear first at about one year of age. Moreover, the newest findings from our laboratory provide evidence suggestive of vocal imitation in young infants. These new findings, coupled with the need for programmatic studies of imitation, motivate the research proposed here. We propose to study two different kinds of imitative acts, gestural and vocal. And while each of the two areas has very specific concerns guiding the design of the experiments, we are impressed with the concerns that are common to both. Examples of these common concerns are (1) the range of responses that are imitated, (2) the specificity of the imitated response, (3) the nature of the stimulus most effective in eliciting an imitated response, and (4) the effects of experience on imitation. The goal is to bring together expertise from two separate disciplines, developmental psychology and speech and hearing sciences. We propose an integrated series of experiments on gestural and vocal imitation over the first year of life.